Bag-making machinery

ABSTRACT

In bag-making machinery for bags with cross-bottom folds, rotating means are provided between a tube-forming machine for making tube sections and a folding machine for forming the crossbottom folds. The rotating means serve to turn each tube section from a longitudinal position in which it leaves the tube-forming machine to a transverse position in which it must pass through the folding machine. The rotating means comprise two superposed rotating devices, deflecting means being provided upstream of said devices for allocating the tube sections alternately to each device, and a pair of conveyors being provided downstream of the devices for transferring the transversely fed tube sections in a row onto a conveyor of said folding machine.

United States Patent Kuckhermann et a1.

[ Mar. 18, 1975 1 BAG-MAKING MACHINERY [76] Inventors: Gustav Kuckhermann, Goethestrasse 24;Richard Feldkamper, Wielandstrasse 5 Walter Paul, Bahnhofstrasse 101;Friedrich Franz Brockmuller, Diersmannsweg 54, all of 454 Lengerich, Westphalia, Germany [22] Filed: Sept. 6, 1973 v [21] Appl. No.: 394,816

[30] Foreign Application Priority Data Sept. 11, 1972 Germany 2244561 [52] US. Cl. 93/27, 93/8 R [51] Int. Cl. 1331b 1/08 [58] Field of Search 93/8 R, 14, 18, 21, 22,

[56] References Cited UNITED STATES PATENTS 1,926,421 9/1933 Andreas 93/14 3,556,518 1/1971 Brockmueller et a1. 271/64 3,566,754 3/1971 Stork et a1. 93/8 R 5/1971 Richter 93/8 R 3,618,477 11/1971 Piazze et a1. 93/8 R FOREIGN PATENTS OR APPLICATIONS 1,150,567 6/1963 Germany Primary E.\'aminerRoy Lake Assistant Examiner-James F. Coan Attorney, Agent, or Firm-Fleit & Jacobson [57] ABSTRACT In bag-making machinery for bags with cross-bottom folds, rotating means are provided between a tubeforming machine for making tube sections and a folding machine for forming the cross-bottom folds. The rotating means serve to turn each tube section from a longitudinal position in which it leaves the tubeforming machine to a transverse position in which it must pass through the folding machine. The rotating means comprise two superposed rotating devices, de-,

fleeting means being provided upstream of said devices for allocating the tube sections alternately to each device, and a pair of conveyors being provided downstream of the devices for transferring the transversely fed tube sections in a row onto a conveyor of said folding machine.

3 Claims, 3 Drawing Figures PAY EHT HAR I 8 i975 SHEET 2 OF 2 FIG. 3

1 BAG-MAKING MACHINERY The invention relates to machinery for making bags having cross-bottom folds, comprising a tube-forming machine for making single or multi-ply tube sections from paper or plastics film and discharging the tube sections longitudinally, means disposed downstream of the tube-forming machine for rotating the discharged tube sections through 90 into a transverse position, and a folding machine disposed downstream of the retating means for forming the folds at one or both ends of each transversely-fed tube section.

The interpositioning of rotating means, such as those described in German Specification No. 1,586,347, between the tube-forming machine and the folding machine brings about the considerable advantage that these three components of the bag-making machinery can be arranged in a straight line, which is the optimum arrangement in a factory from the point of view of saving floor space.

However, the rotating means make it necessary for the tube sections, after these have been severed from a tubular web, to be brought to a significantly-larger spacing from one another so as to permit them to be rotated freely through 90. More particularly, this spacing must beso large that even the longest tube sections that are to be processed by the machinery will not be obstructed as they are turned by the rotating means. This requirement calls for a correspondingly large spacing between turntables which form part of the rotating means. Further, with a given production rate, ie with a given cycle for the bag-making machinery, the spacing between the turntables demands a particular translatory speed to be executed by the turntables, the linear speed being considerably higher than the speed with which the tubular web is being fed in the tube-forming machine. With such an increased linear speed in the rotating means, considerable difficulties arise during rotation of the tube sections, especially if the latter are made from flimsy and flexible materials. At the leading edges of the tube sections, the rotary speed and higher linear speed give, rise to a very high total speed, with the result that the leading edges of the tube sections tend to rise under air currents and are often folded back through 180. The proper processing of the tube sections in the folding machine then becomes impossible.

This disadvantage cannot be avoided by reducing the rotary speed of the tube sections which, in any case, can be achieved only by making the rotating means considerably longer and thereby increasing their cost and space requirement. The free translatory movement of the individual bag sections at the high production rates that are nowadays required would alone be responsible for fluttering of the leading ends when the bag material is particularly flimsy. Thus, displacement of the bag sections in the rotating means is likely to occur if their linear speed is not also reduced, but this would lead to an unpermissible reduction in the pro duction rate.

The invention aims to avoid fluttering ofthe tube sections during their rotation even in the case of high production rates.

means disposed downstream of the tube-forming machine for rotating' the discharged tube sections through 90 and thereby locating them for subsequent feeding in a direction transversely of their lengths, and a folding machine disposed downstream of the rotating means for forming said folds at one or both ends of each transversely-fed tube section, wherein said rotating means are formed by a dual rotator comprising two superposed rotatingdevices, deflecting means being providedupstream of said devices for allocating the tube sections alternately to each device, and a pair of conveyors being provided downstream of the devices for transferring the transversely-fed tube sections in a row onto a conveyor of said folding machine.

By reason of theprovision of a dual rotator using rotating devicesvin two different operating planes, the intervals between the turning stations in the rotating means can be halved without the individual tube sections obstructing one another during rotation. Accordingly, the rotating means can operate with half the translatory speed that would otherwise be necessary. This reduction in operating speed not only minimises the danger of fluttering of the leading ends of the workpieces but also permits the rotating means to have a shorter structural length. Further, the lower operating speed of the rotating means increases the life of this complicated equipment, because wear will be less.

Each rotating device preferably includes conveyor means effective to subject the tube sections to translation during rotation, the conveyor means of both said devices being operative at a suitable constant speed which avoids fluttering of the leading ends of the tube sections during rotation. Since tube sections having different lengths are discharged from the tube-forming machine at correspondingly different speeds, each rotating device is'preferably provided upstream thereof with a pair of rollers for bringing the tube sections to the constant speed of the conveyor means before engagement by said devices, the rollers being of course turned at the exactly required speed. In this way, each tube section will be engaged exactly at the point about which it is to be rotated, regardless of the speed with which it is discharged from the tube-forming machine. The constant linear speed of the rotating means also simplifies transfer of the transversely-fed tube sections to the folding machine and the required accurate setting of the spacings between the transverse tube sections during feeding through the folding machine.

The proper allocation of the tube'sections leaving the tube-forming machine to the individual rotating devices calls for a special construction of the deflecting means, it being borne in mind that the end-to-end spacing between the tube sections is quite small as they leave the tube-forming machine. More particularly, a deflector must be moved very rapidly to alternate the supply of tube sections to the rotating devices and it According to the invention, bag-making machinery film and discharging the tube sections longitudinally,

must be possible to set the deflector very accurately. Preferably, the deflecting means comprise a deflector tongue displaceable within limits, an actuating lever for displacing said tongue, a reciprocatable rod on which there are two substantially coaxial storage springs, said lever being interposed between said springs, wherein, whilst one of the springs is being stressed during reciprocating movement of the rod, the actuating lever engages one side of a pivotable locking finger and, whilst the other spring is being stressed, the actuating lever engages an opposite side of said finger, the spacing between the finger sides determining the limiting positions of the tongue and the finger being intermittently pivoted insequence with the cycle of the machinery so that it releases the actuating lever to deflect the tongue under the influence of one of the stressed springs just before each tube section reaches the tongue.

An example of the invention will now be described with reference to the accompanying diagrammatic drawings, wherein:

FIG. 1 is a side elevation of bag-making machinery employing a jaw rotator;

FIG. 2 is a plan view of the tube sections that are being fed through the bag-making machinery of FIG. 1; for the purpose of clarity, the tube sections passing through the upper of the two rotating devices are shown in full lines and those passing through the lower rotating device are shown in chain-dotted lines; and

FIG. 3 is an enlarged side elevation of deflecting means to be used with the FIG. 1 machinery for alternately supplying the rotating devices with tube sections arriving from a tube-forming machine.

The illustrated bag-making comprises a tube-forming machine 1, a jaw rotator 2 for tube sections coming from the machine 1, and a folding machine 3 for forming cross-bottom folds at one or both ends of each tube section. The machines 1 and 3 are of known construction and are therefore not illustrated in detail.

The tube-forming machine 1 fabricates a continuous single or multi-ply tubular web of flat material such as paper or plastics film, provides this web with any necessary adhesive coatings and with transverse perforations at intervals corresponding to the desired lengths of the bags to be made, and severs individual tube sections S along the transverse perforations with the aid ofknown severing means. A belt conveyor 4 discharges the tube sections S at very close spacings from one another in the longitudinal direction.

The folding machine 3 forms folds, preferably crossbottom folds, at at least one end of each tube section S. For this purpose, it is necessary or desirable that the tube sections S be fedin a direction transversely of their lengths and at a particular spacing r from one another.

The jaw rotator 2 serves to turn the longitudinally-fed tube sections S through 90 after they have left the machine 1. It comprises two like superposed rotating devices 5 ans 5 of a construction known from German Specification No. 1,586,347. Each rotating device comprises a double chain conveyor 51, 51 or 52, 52'

of which the individual chains are equipped with turntables 6, 6 and 7, 7', respectively, at equal centre-tocentre spacings .r. The double chain conveyors are moved at a constant speed in the direction of the arrow I a. The individual chains are set relatively to one another so that their turntables become accurately superposed in the respective conveying planes of the double chain conveyors (as best seen in FIG. 1). The turntables of the double chain conveyor of the device 5 are offset with respect to those of the double chain conveyor of the device 5 by a distance equal to .r/2. The turntables are provided with control levers fixed to their rotary shafts and these engage stationary control cams 8,8 constructed so that, as each turntable is conveyed lengthwise of the rotating means by the chains, it is rotated accurately through 90.

Upstream of the rotating means there is a deflecting tongue 9, which can be oscillated within limits in sequence with the operating cycle of the machine, and an intermediate belt conveyor 10 or 10 for each of the rotating devices, as well as a pair of rollers 11 or 11', respectively. At least one roller of each pair is rotated at a peripheral speed such that a tube section passing therebetween is fed at exactly the same speed as the linear speed of the conveyor chains in the rotating means. The rollers of each pair may be circular cylindrical and intermittently brought into contact with one another for a short period in sequence with the operating cycle of the machine. In the illustrated construction. however, one roller of each pair is of circular cross-section and the other roller is provided with a sector-shaped projection, the two rollers of each pair being spaced from'one another so that only the sector of one of the rollers will make contact with the periphery of the other roller.

Downstream of the rotating means 2 there is a pair of belt conveyors l2 and 12' for each rotating device for the purpose of transferring the transversely-fed tube sections S from the rotating devices in a row onto an aligning conveyor 13 of the folding machine 3. The aligning conveyor 13 is of known construction and is moved at a lower feeding speed than the pair of belt conveyors 12, 12. Also, the conveyor 13 is provided with transverse bars 14 at equal intervals; these accurately align the tube sections as they arrive from the rotating devices 5 and 5'.

The longitudinally-fed tube sections S discharged from the machine 1 on the conveyor 4 are alternately deflected by means of the tongue 9 towards the intermediate conveyor belts 10 and l0of the upper and lower rotating devices 5 and 5', respectively. They pass between the respective pairs of rollers 11 and 11 which,just before the tube sections are successively engaged by the pairs of turntables 6, 6 or 7, 7', bring the tube sections to a linear speed that is the same as the constant linear speed of the chain conveyors 51, 51' or 52, 52', the tube sections being accurately aligned centrally of the respective pairs of turntables. During translation of the tube sections in the devices 5, 5, the control cams 8,8 cause the turntables to be rotated accurately through whereby the tube sections assume a transverse position before they are transferred to the conveyors 12 and 12 which throw the tube sections onto the aligning conveyor 13. Since the latter is moved slowly in comparison with the conveyors 12, 12', the leading edge of each tube section will strike one of the bars 14 of the conveyor 13. This causes each tube section to become accurately aligned and also accurately spaced from the adjoining tube sections by the centreto-centre spacing t which is essential for proper operation of the folding machine 3.

The allocation of the longitudinally and rapidly fed and closely spaced tube sections to the individual rotating devices 5, 5 calls for very rapid oscillation of the deflector tongue 9 between the two limiting positions thereof. The drive for the tongue therefore requires a special construction, as diagrammatically illustrated in FIG. 3. Anactuating lever 15 for the tongue 9 engages between two storage springs 16, 16' which are threaded onto a common rod 17 and the free ends of which are supported between collars on the rod. The rod is reciprocated in a longitudinal direction by a cam drive 18, 19 which turns at twice the speed of the operating cycle of the bag-making machinery. Near the free end of the actuating lever 15 there is a finger 20 which, by means of a cranked lever 21 and a cam drive 22, 23, is moved up and .down once during each operating cycle of the machine. In its upper position the finger 20 locks the actuating lever 15 and in its lower position it releases it. The two crank drives 18, 19 and 22, 23 are set relatively to one another so that the finger 20 will release the actuating lever 15 in both dead-centre positions of the drive 18, 19 or rod 17.

In the condition as illustrated in FIG. 3, the tongue 9 is disposed in its lower limiting position and a tube section S is being deflected towards the upper interme-' diate conveyor 10 for feeding to the upper rotating device 5. The lever engages the left-hand side 24 of the finger 20. Whilst the tube section S is being fed to the upper intermediate conveyor 10, the storage spring 16 is being stressed under the action of the crank drive l8, l9 moving the rod 17 towards the right-hand side. immediately before arrival of the next tube section at the tongue 9, the finger 20 will release the lever 15. This enables the spring 16 to impel the lever 15 in an anticlockwise direction so as to fling the tongue 9 to its upper limiting position so that the next tube section will be deflected downwardly to reach the pivoting device 5'. As the finger 20 is moved upwardly again, the lever 15 will engage the right-hand side thereof so that, after the crank drive 18, 19 has passed its right-hand dead-centre position, the spring 16will start to be stressed. The distance between the sides 24 and 25 of the finger 20 determines the two limiting positions of the tongue 9. To prevent excessive displacement of the lever 15 by either of the springs 16, 16', two auxiliary stops 26, 27 are provided.

We claim: 7

1. An apparatus for making bags with cross-bottom folds comprising a tube-forming meansfor making tube sections having at least one ply from flat sheet material selected from the group consisting of paper and plastic film and discharging the tube sections longitudinally, rotating means positioned downstream of the tubeforming means for rotating the discharged tube sections 90 while maintaining the tube sections in sub- I two superposed rotating devices, deflecting means positioned upstream of said rotating devices for directing the tube sections alternately to each device, and a pair of conveyors positioned downstream of the devices for transferring the transversely-fed tube sections in a row onto the conveyor of said folding means.

2. The apparatus of claim 1 wherein each of said rotating devices includes conveyor means effective to subject the tube sections to translation in a direction generally toward said folding means during rotation, the conveyor means of both said devices being operative'at a constant speed, and wherein each said devices is provided upstream thereof with a pair of rollers for bringing the tube sections to said constant speed before engagement by said devices.

3. The apparatus of claim 1 wherein said deflecting means comprises a deflector tongue moveable within limits, an actuating lever for moving said tongue, a reciprocat'able rod, two substantially coaxial storage springs mounted on said rod and adapted to be stressedunder the influence of one of the stressed springs just before each tube section reaches the tongue. 

1. An apparatus for making bags with cross-bottom folds comprising a tube-forming means for making tube sections having at least one ply from flat sheet material selected from the group consisting of paper and plastic film and discharging the tube sections longitudinally, rotating means positioned downstream of the tube-forming means for rotating the discharged tube sections 90* while maintaining the tube sections in substantially the same plane, said rotation positioning the tube sections for subsequent feeding in a direction transversely of their length, and folding means including a conveyor positioned downstream of the rotating means for forming said cross-bottom folds at at least one end of each of the transversely-fed tube sections, said rotating means including a jaw rotator comprising two superposed rotating devices, deflecting means positioned upstream of said rotating devices for directing the tube sections alternately to each device, and a pair of conveyors positioned downstream of the devices for transferring the transversely-fed tube sections in a row onto the conveyor of said folding means.
 2. The apparatus of claim 1 wherein each of said rotating devices includes conveyor means effective to subject the tube sections to translation in a direction generally toward said folding means during rotation, the conveyor means of both said devices being operative at a constant speed, and wherein each said devices is provided upstream thereof with a pair of rollers for bringing the tube sections to said constant speed before engagement by said devices.
 3. The apparatus of claim 1 wherein said deflecting means comprises a deflector tongue moveable within limits, an actuating lever for moving said tongue, a reciprocatable rod, two substantially coaxial storage springs mounted on said rod and adapted to be stressed by the reciprocation of said rod, said lever being interposed between said springs, a pivotable locking finger cooperating with said lever, said lever engaging one side of said locking finger while one of said springs is being stressed and the other side of said finger when the other of said springs is being stressed, the spacing between the sides of said finger determining the limiting positions of said tongue, said finger being intermittently pivoted in sequence with the cycle of the apparatus so that it releases the actuating lever to deflect thE tongue under the influence of one of the stressed springs just before each tube section reaches the tongue. 